Cable's message was the only one with weight

Despite all the advance publicity, only Vince Cable unveiled specific suggestions for public spending cuts today as Britain moves to start paying off the billions it borrowed to rescue prodigal bankers. Safe in the knowledge that a Liberal Democrat is unlikely to be running the Treasury, even he spoke of "potential savings" – not "cuts" – that could be made in areas from Trident missiles to the middle class welfare state.

By comparison, Gordon Brown and George Osborne stuck to what Cable dismisses as "generalities" when they addressed their target audiences, the Spectator magazine and the TUC.

Brown sounded keener on spending pledges and taxing the rich than fleshing out those "hard choices" he mentioned in passing. Osborne's "strategy for recovery" contained nothing new and his tone was defensive.

At least the major parties are edging towards specifics with barely 200 days before the election campaign begins. Labour officials whisper that expanded maternity leave will be postponed. David Cameron earns easy headlines by canning ID cards and promising to double the price of lager in Westminster bars, unaware that it is being rent-free that makes the bar beer so cheap.

Not unreasonably, the Tories are waiting to see what specifics Alistair Darling produces in his November pre-budget report while promising – as Osborne did again yesterday – an emergency budget next June when any unpopular slash-and-burn plans can safely be blamed on Labour's legacy. They are being no less "shifty" than Brown.

Which leaves Cable. Number crunchers at the respected Institute for Fiscal Studies, whose own estimate of the required squeeze will be published tomorrow, call his nine suggestions a "state-of-the-art shopping list". As so often with Lib Dem ideas, it includes some which bigger parties are closing in on: trimming tax credit for better-off families, curtailing ID cards and the NHS IT system, freezing public sector pay (TUC please note) and ending £28bn worth of subsidy to public sector pensions (ditto).

Today, Bob Ainsworth, the defence secretary, hovered over another Lib Dem option, not to cancel the Trident nuclear upgrade, but cut the number of boats. Cable would also gouge other procurement plans, Euro-fighters, Nimrod reconnaissance aircraft which protect our boys in the field. The Tories are making similar noises. So is the Treasury. Another target – NHS "bureaucrats" – is on everyone's list.

Voters routinely tell pollsters they want spending cuts (for others) over tax hikes (for themselves). All such cuts carry consequences which may not be so popular on the day, or even save much money. Thus taxing middle class child benefit, for example, might be "fair" but not worth the political cost of curbing a universal benefit that helps the poorest most.

For all that Osborne accuses Darling of irresponsible spending as the recession eases, he is already raising taxes in 2010 when two-thirds of the £30bn extra spending will be on unavoidable benefit costs and interest payments items – which chancellor Osborne would find very hard to cut.